Mode of preventing accidents from the explosions oe stbaiff-boiless by



UNTED TATFS PATENT FFltE PHILIP C. FRIESE, OF BALTIMORE, MARYLAND.

MODE 0F PREVENTING ACCIDENTS FROM THE EXPLOSINS OF STEAM-BOILERS BYSURROUNDING THEM VITH A JACKET.

Speccation of Letters Patent No. 1,118, dated April 10, 1839;

To all 'whom it may concern Be it known that I, PHILIP CHRISTOPHERFinnen, of the city of Baltimore and State of Maryland, have invented anew and improved mode of preventing injury to persons and property bythe steam, hot water, and fragments rushing and cast from steamboilersin the act of exploding; and l do hereby declare that the following is afull and exact description.

The nature of my invention consists in providing a steam boiler with ajacket of peculiar construction, which will be hereafter described, andtaking advantage of two principles, one of which is the elasticity ofsteam, the other is the principle of relation with regard to thedifference of strength between the boiler and the jacket.

To enable others skilled in the art to make and use my invention l willproceed to describe first its construction, and secondly its operation.

First, to arrive at a clear understanding of the construction of myinvention, it is necessary to premise that the steamboiler (representedin the accompanying drawings by L, M, N, O) to which it is to beattached may be made in any of the known forms and provided with safetyvalve (V) and gagecocks and steam cocks (m, y, and the other appendagesof such boilers. But in order to prevent the injury to persons andproperty always at present attendant. on the explosion of a steamboiler(L, M, N, O) and caused by the steam, hot water and fragments of theboiler, l inclose it with a jacket (A, B, C, D) of boiler iron or othermetal. The peculiarities in the structure of this metallic jacketconsist in three things: First, in its surrounding every part of theboiler and being held at a convenient distance from it by stays (Vif,WV, W.) Secondly, in its being provided with a convenient number ofvents, which vents are fitted with pipes (E, F, G) bent to whateverdirection it may be considered most harmless to lead the steam in theevent of an explosion of the boiler. Thirdly, in its being capable ofresisting on every square inch a pressure (say ten per cent.) greaterthan the maximum bearable on every square inch of the boiler.

The combination of the above three peculiarities constitute theprinciple of the construction of my invention. But for the purpose ofpresenting my idea more at large to the understanding l will describesome minor details concerning the furnace door, draft hole, safetyvalve, gageand steamcocks, manholes, steam pipe and smokestack; althoughthese particulars do not form any part of my invention but are merelyconsequences arising from its application and may be altered accordingto the suggestions of convenience or opinion.

The furnace door (P) is in the jacket and is composed of two leavesopening toward the furnace (U) and when closed will resist as muchpressure from within as any other part of the jacket. Weights (R, R,)are attached to the door continually tenuing to close it, so that itonly remains open while fuel is passing through into the furnace. rihedraft hole (Q) is also in the jacket an dis furnished with a shutter (S)hung on the top of the draft pole. rlhis shutter is balanced by a weight(T) which may rest on a sliding shelf (ai), by which means the draft canbe regulated. From the fact, that the shutter is nearly balanced by aweight7 it will appear that the slightest draft from the inside willclose it. `When the shutter is closed it is as strong as any other partof the jacket.

For the purpose of preventing any communicating with the furnace exceptthrough the furnace door (P,) and the draft hole (Q), a `sheet of metal(c CZ) is placed on the bottom of the furnace door and extended to thebottom of the mouth of the furnace (U), another sheet (O b) extends fromthe top of the furnace door to the top of the mouth of the furnace, athird sheet (O c CZ) extends from one side of. the furnace door to thecorresponding side of the mouth of the furnace, a fourth sheet (likewiserepresented by O Z) c (Z) extends from the remaining side of the furnacedoor to the remaining side of the mouth of the furnace. These foursheets of metal form a casing that cut off all communication exceptthrough the door (P) and the furnace grate (7L c). A similar casingextends from the draft hole (D to the innermost extremity of the furnacegrate (7L c). rllhe top sheet (0 d) is the same as the bottom sheet ofthe above described casing for the furnace door, the bottom plate is (gf), the side plates or sheets are both represented by (It g f d);

the back plate is (ft g.) The ashes fall through the furnace grate (h c)on the bottom plate (g f) of the draft hole casing.

The safety Valve apparatus (V) is contained in the space between theboiler and the jacket and by means of a graduated limb (K) attached tothe lever and protruding through the jacket makes known its motion. Thegageand team-cocks (X, Y, Z) extend by a neck through the jacket.

The pipe that yconveys the steam from the boiler to the engine isrepresented by (I) and goes through the jacket, as does also thesmokestack (I-I).

Secondly, the operation of my invention is founded upon the elasticityof steam and the relation existing between the strength of the boilerand of the jacket. From the nature of an elastic body it follows thatthe steam within the boiler can in no. one instant of time acquire morethan aninfinitely small degree greater power than the maximum bearableby the boiler. At this instant the boiler must give way and the steam,hot water and fragments will be forced against the jacket by the powerof the steam at the moment of explosion. But the jacket is stronger thanthe projecting power and will consequently withstand the shock, unlessthe steam can acquire an increase of power. The last-ic quality of steamprevents, however, any increase, because the moment 'a rupture takesplace in the boiler, the steam will lill the intervening space betweenthe boiler and the jacket and by expansion through the large pipes (E,F, G,) rapidly lose all its power. When a flue (0 j? g) 4bursts, thesteam, &c., escapes through the smokestack (H). Vhen there is more thanone boiler they may be all enveloped with one common jacket, thestrength of which must be (say ten per cent.) greater than that of thestrongest boiler.

IVhat I claim asmy invention and desire to secure by Leters Patent isthe application to steam boilers of a jacket possessing in itsconstruction the following three peculiarities, viz:

l. This jacket must envelop the steamboiler entirely leaving throughouta certain intervening space between the jacket and the boiler.

2. This jacket must have a convenient number of holes in it, each holeto be fitted with pipes bent to whatever direction it may in each casebe considered most harmless to lead the steam in the event of anexplosion of the boiler.

3. This jacket must be able to resist on every square inch of its innersurface al pressure somewhat greater than the maximum that can bewithstood on every square inch of the boiler.

PHILIP C. FRIESE. Witnesses:

WM. I. PRESTON, PHILIP It. J. Finnen.

